DEFINE GPS Trial: Physiologic PCI Guidance, Co-Registration, & Surprising Case Lessons

How often do patients leave the cath lab with residual ischemia—and can physiologic guidance change outcomes?In this discussion, Dr. Chris Brown and Dr. Christian McNeely review insights from the DEFINE GPS Trial, where PCI guided by pressure wire co-registration was compared with angiography alone.Key highlights:- Why 20% of patients left the lab with residual ischemia in DEFINE PCI- How FFR/iFR pullback and co-registration create a physiologic roadmap for stenting- Trial design, enrollment (2,100 patients), and endpoints: MACE at 1–2 years- Surprising cases where physiology overturned angiographic impressions- Calcium, long lesions, and the limits of angiography alone- When to trust physiology vs imaging—IVUS/IVL integration- The future role of co-registration software in routine PCIThis is a must-watch for interventional cardiologists looking to integrate objective physiologic data into daily practice.Like and subscribe to see more!Follow the MurmurMD Youtube for more tips: https://www.youtube.com/channel/UCfrLYhAhliQ2ZvXinkDCZvADownload the MurmurMD app here: https://apps.apple.com/app/apple-store/id1586692687?pt=123231498&ct=curtis&mt=800:00 – Intro & guest background 00:39 – Define GPS trial design & objectives 01:17 – Residual ischemia: lessons from Define PCI 02:23 – Co-registration system explained 03:09 – Inclusion criteria & patient population 03:53 – Endpoints: MACE at 1–2 years 04:07 – Enrollment: 2,100 patients, top enrolling sites 04:25 – Why angiography alone misses physiology 05:12 – Standard PCI workflow vs physiologic pullback 06:30 – Case 1: circumflex calcification & LAD ischemia 07:41 – Co-registration mechanics step-by-step 09:12 – Post-PCI IFR goals & physiologic success 11:31 – IVUS co-registration and stent sizing pearls 12:46 – Calcium, long lesions & turbulence effects 13:43 – Taking subjectivity out of angiography 15:22 – Physiology + imaging: additive or redundant? 16:43 – Aggressive stent sizing & perforation risk 17:28 – Case 2: non-STEMI with PDA & focal circ lesion 18:51 – Pullback showing ischemia dots at stenosis 20:10 – Why physiology prevented unnecessary stenting 21:49 – Which lesions should we defer vs treat? 22:17 – Looking ahead: Define GPS trial results (2026–27)#DefineGPS #PCI #InterventionalCardiology #FFR #iFR #CoRegistration #CathLab #StructuralHeart #StentOptimization #MurmurMD